Gas turbine engines



Sept. 15, 1964 Y J. M. s. KEEN 3,148,594

GAS TURBINE ENGINES Filed May 1, 1962 5 Sheets-Sheet 1 h winter wwsa y WA tlorneya Sept. 15, 1964 J. M. s. KEEN GAS TURBINE ENGINES 3Sheets-Sheet 2 Filed May 1', 1962 Attorneys Se t. 15, 1964 J. M. s. KEENGAS TURBINE ENGINES 3 Sheets-Sheet 3 Filed May 1, 1962 Attorneys UnitedStates Patent 3,148,504 GAS TURBINE ENGINES John Michael Storcr Keen,Allestree, England, assignor to ll toils-Royce Limited, Derby, EnglandFiled May 1,1962, Ser. No, 191,602 Claims priority, application GreatBritain May 4, 1961 i 13 Claims. (Cl. 60'-39.31)

This invention relates to gas turbine engines.

According to the present invention a gas turbine engine includes at oneend of the engine a central fairing or bullet supported from an outercasing or wall by one or more struts which extend across an annularspace formed between the casing or wall and the fairing or bullet, saidfairing or, bullet and/or said struts being formed in two or more piecesdetachable from each other so that when at least one piece is removedaccess is given to the interior of the fairing or bullet and/or eachstrut.

Preferably each strut is divided so as to form a leading edge portionand a separate trailing edge portion and the fairing or bullet isdivided so as to form a front or nose portion and a separate nearportion.

The leading edge portion of each strut is preferably formed as anintegral part of the front or nose portion of the fairing or bullet andthe trailing edge portion is formed as an integral part of the rearportion of the fairing or bullet.

The outer end of each leading edge portion of each strut is preferablydetachably mounted on the casing or wall.

The abutting edges of the leading and trailing edge portions of thestruts and the abutting edges of the front or nose portion andrearportion of the fairing or bullet may be provided with sealing means toprevent air or gas flowing into the interior of the struts and fairingor bullet.

The sealing means may comprise a sealing strip secured to either thedetachable portions or said fixed portions and extending beyond theedges of the surfaces which abut the other portions, the edge of saidstrip which extends beyond said abutting surfaces being received betweenthe internal surface of the other portions and a surface provided on afurther sealing strip secured to the other portions.

Preferably the sealing means comprises a sealing strip secured to thedetachable portions and extending beyond the edges. of the surfaceswhich abut the fixed portions, the edge of said strip which extendsbeyond said abutting surfaces being received. between the internalsurface of the fixed portions and a surface provided on a furthersealing strip secured to the fixed portion.

Preferably the central fairing or bullet is situated in the air intakeleading to a compressor system of the engine, units such as the fuelcontrol unit and starter motor unit for said engine being housed withinsaid fairing or bullet, conduits leading to and from said unitsextending through said struts, said leading edge portions of the strutsand said front or nose portion of said fairing being removable to giveaccess to said units and conduits.

In one particular arrangement the front or nose portion of the fairingis secured by studs and nuts to said starter or fuel control unit.

The fairing or bullet, struts and casing or wall may be formed fromfibres of glass or asbestos impregnated with phenolic or epoxy resins.The leading edge of the struts may be strengthened by a foamed syntheticresinous material located between the inner surface of the leading edgeand the sealing strips secured to the leading edge portion.

The gas turbine engine may be a vertically mounted engine whosepropulsive gas stream is directed vertically $348,504 Patented Sept. 15,1954 fairing and struts shown in FIGURE 1, sealing means;

being omitted for clarity,

FIGURE 4 is a view similar to the one shown in FIG- URE 3 showing thesealing means, but omitting the starter and fuel control units forclarity,

FIGURE 5 is a section taken on the line 55 indicated on FIGURE 4, and

FIGURE 6 is a view taken in the direction of the arrow 6 indicated onFIGURE 4.

The gas turbine engine shown in FIGURES 1 and 2 comprises an axial flowcompressor 10 which receives, air from an air intake 11 and suppliescompressed air to combustion equipment 12 where fuel from injectors 13is burned in the air, the products of combustion pass to a turbine 14 todrive it before passing to atmosphere through a propulsion nozzle 15;The turbine 14 drives the compressor 10 through a shaft 16.

The intake 11 comprises a central fairing 17 which is supported from anouter wall 18" by two struts 19.

Mounted within the fairing 17 is a starter motor unit 20' and a fuelcontrol unit 21 which supplies fuel to the injectors 13 through conduits22 which pass through the struts 19. i

As will be seen more clearly from FIGURES 3 to 6 the fairing 17 isdivided into a front portion 17a and a rear portion 17b. Each strut 19isdivided into a leading edge portion 19a and a trailing edge portion19b. The leading edge portions 1a are formed as an integral part of thefront portion 17a. and the trailing edgeportions are formed as anintegralpart of the rear portion 17b.

When the parts are assembled the leading and trailing edge portions 1%,19b and the front and rear portions 17a, 17bv abut each other onsurfaces indicated at 23.

In order to prevent air within the intake 11 passing into the'interiorof the struts 1h and fairing 17 the surfaces 23 are sealed bysealingmeans 24 (FIGURES 4 and 5). In these figures the units 20, 21have been omitted for clarity. The seal 24 comprises a sealing strip 25which is secured to the leading edge portions 19a and the front, portion17a. The strips 25 extend beyond the surfaces 23. Secured to thetrailing edge portions 19b are sealing strips 26 which have portions 26awhich diverge from the internal surface of the portions 1%. The portionsof the strips 25 which extend beyond the surfaces 23 are receivedbetween the portions 26a and the internal surface of the portions 1%.

Instead of securing the sealing strip 25 to the leading edge portion 19ait may be carried by thetrailing edge portion 1% so as to have a portionextending forwardly beyond the surfaces 23. In such an arrangement thesealing strips 25 are carried by the leading edge portions 19a. Thisarrangement has the advantage that the gas flow acts on the overlappingportions in a direction urging them together.

The leading edge of the portions 19:: may be strengthened by having afoamed synthetic resinous material located between the inner surface ofthe portion 19a and the sealing strips 26.

Secured to the rear portion 17b of the fairing 17 is a sealing ring 27and the front edge of the ring overlaps the strips 25.

The outer end of the trailing edge portions 1% of the struts 19 aresecured to the outer wall 18, and the leading edge of the wall 18 isprovided with a mounting block 28 to which is secured a member 29secured to the outer end of each leading edge portion 19b. The mountingblock 23 and the member 29 are secured together by set screws 30.

As will be seen more clearly from FIGURE 3 the front portion 17a of thefairing is secured to the starter motor unit 20 by nuts 31 which engagewith studs 32. The fuel control unit 21 is secured to fixed structure bymeans not shown.

In order to remove the front portion 17a and the leading edge portions19a the set screws 30 and the nuts 31 are removed allowing the portions17a and 19a to be moved axially to the left as viewed in the drawings.When the portions 17a, 19a have been removed access is given to theunits 20, 21 and also the conduits 22.

What we claim is:

1. In a gas turbine engine having an outer casing enclosing compressormeans, combustion means, and turbine means: a central fairing at one endof the engine, at least one strut extending across an annular spaceformed between the casing and the central fairing for supporting thecentral fairing from the outer casing, said fairing and said at leastone strut each being formed in at least two pieces detachable from eachother so that when at least one piece is removed, access is given to theinterior of the fairing and the strut.

2. A gas turbine engine as claimed in claim 1 in which said two pieceswhich form said central fairing define a nose portion and a separaterear portion and in which said two pieces which form said strut define aleading edge portion and a separate trailing edge portion.

3. A gas turbine engine as claimed in claim 2 in which said leading edgeportion of said strut is formed as an integral part of said nose portionof said central fairing and said trailing edge portion of said strut isformed as an integral part of said rear portion of said central fairing.

4. A gas turbine engine as claimed in claim 2 including means fordetachably connecting said leading edge portion of said strut at itsouter end to said casing.

5. A gas turbine engine as claimed in claim 2 including sealing meansbetween abutting edges of said leading edge portion and said trailingedge portion of said struts and between abutting edges of said noseportion and said rear portion of said central fairing for preventingflow of fluid into the interior of said strut and said central fairing.

6. A gas turbine engine as claimed in claim in which said sealing meansincludes a sealing strip secured to one of said leading portion and saidtrailing portion of said strut and to one of said nose portion and saidrear portion of said central fairing and extending beyond the abuttingedges of said leading portion and trailing portion of the strut and saidnose portion and rear portion of said central fairing, and a secondsealing strip secured to the other of said leading portion and saidtrailing portion of said strut and to the other of said nose portion andsaid rear portion of said central fairing for receiving saidfirst-mentioned sealing strip between the same and the internal surfaceof the other of said leading portion and trailing portion of said strutand the other of said nose portion and rear portion of said centralfairing.

7. In a gas turbine engine having an outer casing enclosing compressormeans, combustion means, and turbine means: a central fairing at one endof the engine, at least one strut extending across an annular spaceformed between the casing and the central fairing for supporting thecentral fairing from the outer casing, said central fairing being formedof a nose portion and a separate rear portion detachable from eachother, and said strut being formed from a leading edge portion and aseparate trailing edge portion detachable from each other, said leadingedge portion of said strut being formed integral with said nose portionof said central fairing and said trailing edge portion of said strutbeing formed integral with said rear portion of said central fairingwhereby removal of the leading edge portion of said strut and the noseportion of said central fairing gives access to the interior of saidstrut and said fairing, and sealing means between abutting edges of saidleading edge portion and said trailing edge portion of said strut andsaid nose portion and rear portion of said fairing whereby fluid isprevented from flowing into the interior of said strut and said centralfairing.

8. A gas turbine engine as claimed in claim 7 in which said sealingmeans includes a sealing strip secured to one of said leading edgeportions and trailing edge portions of said strut and to said noseportion and said rear portion of said central fairing, said stripextending beyond abutting surfaces between the portions, and a secondsealing strip secured to the other portions of said strut and saidcentral fairing for receiving the first-mentioned sealing strip betweenthe same and the internal surface of the other portions.

9. A gas turbine engine as claimed in claim 8 in which said leading edgeportion of said strut and said nose portion of said central fairing aredetachable from said trailing edge portion of said strut and said rearportion of said fairing and wherein said first-mentioned sealing stripis connected to said detachable leading edge portion of said strut andsaid nose portion of said central fairing and wherein said secondsealing strip is secured to the other portions of said strut and saidcentral fairing.

10. A gas turbine engine as claimed in claim 7 in which said leadingedge portion of said strut is strengthened by a foam synthetic resinousmaterial located between the inner surface of said leading edge and saidsealing means.

11. A gas turbine engine as claimed in claim 7 in which said centralfairing and said strut are positioned at the inlet end of the engine,and including fuel control means positioned in said central fairing andconduits leading to and from said fuel control means extending throughsaid strut.

12. A gas turbine engine as claimed in claim 11 in which said noseportion is secured to said fuel control means by studs and ducts.

13. A gas turbine engine as claimed in claim 7 in which said casing andsaid strut and said central fairing are formed from fibers impregnatedwith resins.

References Cited in the file of this patent UNITED STATES PATENTS2,622,789 Lundquist Dec. 23, 1952

1. IN A GAS TURBINE ENGINE HAVING AN OUTER CASING ENCLOSING COMPRESSORMEANS, COMBUSTION MEANS, AND TURBINE MEANS: A CENTRAL FAIRING AT ONE ENDOF THE ENGINE, AT LEAST ONE STRUT EXTENDING ACROSS AN ANNULAR SPACEFORMED BETWEEN THE CASING AND THE CENTRAL FIARING FOR SUPPORTING THECENTRAL FAIRING FROM THE OUTER CASING, SAID FAIRING AND SAID AT LEASTONE STRUT EACH BEING FORMED IN AT LEAST TWO PIECES DETACHABLE FROM EACHOTHER SO THAT WHEN AT LEAST ONE PIECE IS REMOVED, ACCESS IS GIVEN TO THEINTERIOR OF THE FAIRING AND THE STRUT.